Conventionally, in order to avoid the thermal effect on peripheral components due to radiated heat from the exhaust gas purification device main body for an internal combustion engine, an exhaust gas purification device including a cover for shielding has been known. This cover for shielding shields radiated heat from the exhaust gas purification device main body by covering at least part of the exhaust gas purification device main body.
However, the above-mentioned cover for shielding is provided to contact the exhaust gas purification device main body; therefore, it may generate sound radiation by amplifying the vibration of the exhaust system, and negatively affect the NVH of a motor vehicle. For this reason, technology providing holes in the cover for shielding (for example, refer to Patent Document 1), and technology providing convex ribs to the surface of the cover for shielding (for example, refer to Patent Document 2) have been disclosed, for example.
Patent Document 1: Japanese Patent No. 4094423
Patent Document 2: Japanese Unexamined Patent Application, Publication No. 2002-161739